Hi all, I have some Zu Audio Soul Superflys that I am setting up in a listening area for the bedroom and was wondering if the SuperZen would be a good match?

The speakers are 16 ohm at 101dB and I read a review (Tone Audio #35 - Feb, 2011) that a MiniWatt N3 was a good match, so I was thinking a Decware would be even better (not to mention I like to spend my dollars in America when possible).

However the SuperZen does not have as many watts as the MinWatt N3, so I also thought that the Zen Triode Integrated might be a better match, but it's just that the price of the SuperZen is well within my budget in comparison with the Zen Triode Integrated.

Call Steve and discuss with him. Decware used to offer a choice of output trannys, the standard, good for low impedance loads, and the "EX" version, geared for higher impedance speakers like yours. If your zen has the inappropriate one, you won't get full power to the speakers.

You can select output transformers from the shopping cart when you price a SuperZen.

a) for speakers between 2 and 6 ohmsb) for speakers between 6 and 16 ohms.

It does not change the price.

While it's true running an 8 or 12 ohm speaker with option a) will put less power to the speakers, that is in fact what I sent Tone Audio. The reason the comments were still positive is because the speakers were efficient enough that the reduced power was insignificant.

Obviously SOME speakers are going to fall in the middle and work with either a) or b). That is because a speakers impedance is really a varying load across it's frequency response.

Here is a typical 8 ohm speaker's impedance plot:

You can see around 50 Hz and between 100 & 500Hz the speaker is actually closer to 4 ohms.

Option a) would put out more power as the impedance drops, meaning a nice solid hitting bass and mid bass.

Option b) would put out less power as the impedance drops, making for a leaner sounding bass and mid bass. Low bass below 40 Hz would be slightly improved if the speaker has any real output there.

Of course every loudspeaker's impedance plot is different. And it's only important to know what it is if you plan to run 6 ~ 8 ohm speakers as they fall in the zone where either transformer might sound best.

As a general observation I can tell you that if you have high efficiency single driver speakers that are rated at 8 ohms, option b) is almost always the best, giving the speaker more weight and midrange tone.

Here is a plot of a popular 8 inch fostex driver to support this statement.

Very helpful post, Steve. Could you tell us the optimum impedance for best power transfer for each case, i.e. for the Super Zen, standard output tranny, in stereo, x ohms(?); bridged Super Zen, standard output tranny, x ohms (?); etc. That would be good info to include on the "which amp to choose" page.

Busterfree, do you happen to have an impedance graph for your speakers? If you do, you can use that info, combined what Steve posted, to determine the best match for you. A bridged zen will see half the impedance across the board but the shape of the curve doesn't change. For example, take the first impedance graph that Steve posted of a typical 8 ohm speaker and halve the y-axis impedance scale; now the low areas at 50 hz and from 100-500 hz (the frequencies demanding the bulk of the power) are more like 2 ohms, thus would probably be an excellent pairing with bridged zens. That would provide very good power transfer throughout the primary power band, and give a nice, warm, full presentation. Or so one would reasonably guess, looking just at these few specifics.

Along with Busterfree, I too am still curious as to how bridging affects output impedance. The fact that I distinctly prefer a single zen with my own big box, "8 ohm nominal" impedance, high sensitivity speakers tells me that in spite of the reasoned approach to impedance matching and power delivery, that something else is going on. Specifically, if the output impedance jumps as a result of bridging (not sure if this is the case or not, please correct me), it would be even more reactive into a speaker load. Those of us using big box, three way, high sensitivity speakers (those not specifically designed to be an easy, flat-ish impedance load for SET amps) may be looking this speaker/amp matching issue right in the face.

Unfortunately, I have not found an impedance curve for my speakers yet, but the search continues. I have Klipsch Forte II, Klipsch RB81, and Trapezium speakers. The Forte II are in the closet, and I am using the SE34I.3 with the RB81. I have a small listening space at the moment.

I am just curious more than anything else. The SE84C+ sounded great with the Forte II a while back. I will only have one super zen, and I plan to keep using it with the Trapeziums.

My main speakers are Tekton 8.1en's which are based on the Fostex 206en rated 96dB 1m/1w @ 8ohms. I'm thinking of ordering the SE84CKC which needs a pre-set impedance decision. According to Steve, selection "b" would be the one.

What happens if you run speakers rated at 4 ohms? I currently use the Tektons with my DIYSE84 with plenty of volume with the pot set ~40%. I don't have any speakers rate at 4 ohms, but any speakers available at Decware seem to be around 4 ohms.Regards,Hank

Hey, buster, that's what I have too. With the fortes, the impedance is in the 4 ohm range over the woofer's band below 600hz with a couple peaks down low. The impedance in the midrange (600-6000) is sky high because of the autoformer (and in spite of that, the mid's ridiculous sensitivity still causes it to play a tad hot relative to the woof and tweet when driven with a zen). Corners are your forte's friend to restore the bass, and PWK designed them that way to begin with, so don't be afraid to try it. I prefer the stepped-down tweets and would equalize for that if the amp didn't do it inherently. Forte II w/ a zen is friggin' sick when you get the placement right, and for a small room that's corner loaded, cross-fired slightly in front of the listening position. Get those fuckers out of the damn closet already and hook 'em up!

Buster, I once had the Forte I's with a Select....nice!! I only wish I still had the select when I upgraded the Forte's with Bob Crites' crossovers and diaphragms. If you're keeping your Forte, I'll bet mucho money that the Crites upgrades and the CKC will be the business!! Fresh Sonicaps capacitors go a long way in discharging the signal quicker (less absorption of the signal). Doesn't change the impedance because all values of the caps, resistors, and transformer are the same...just better quality and fresher (not 35 plus years old)

Thanks guys...The Forte II are great. Keeping them in the closet keeps me out of trouble with my neighbors. I am in an apartment. I am the original owner, and I had someone redo the crossovers about 10 yrs ago. I will be upgrading the tweeters and crossover again when I put them back in place. These are a set of speakers that I will never sell...

Ordering my SuperZen right after the New Year ... I guess were both in for a treat!

Not to knock this off topic, but did you see Zu has a new version of the Souls coming out? They are called the Soul Supreme and are topped out nicely. They still have the same super efficient cross-over-less design (i.e. 16ohm and 101dB), but now also share a lot of the same components as their top of the line Dominance and Definition MK IVs - like the Zu103ND/G1-16 full-range driver, the Radian 850 based tweeter and the ZuB3 connector posts.

So many cool things to buy ... too little $$$ ... that's all I'm going to say about that

I've heard a little about them, not much on their website about them yet. I will probably give the new nanotech drivers a try sometime this winter. That will be 2 nice upgrades! Only thing that's been holding me back on the Decware amps is no remote control, as I find myself changing the volume often while listening & reading on my ipad. Recently sold my Cayin A55 integrated with remote, it was very nice. But now I'm ready to see what all the Decware fuss is about! I luv the anticipation of waiting on a new piece of gear!

I have ordered the SuperZen and based on what has already been discussed have selected speaker option B, since the speakers I currently have are nominally rated at 8 Ohms.

For me right now speaker matching and impedance ratings is an unlearned science. So if I were thinking for some time in the future investing in DM945's or MG944's what would be the consequences of the option B?

What's the transformer sound difference you heard with your Zen? I have the new Super Zen and just spoke with Steve about sending mine back for the B because I'm getting distortion at the 1 o'clock volume position, yet the volume is barely reaching my "normal" moderate listening level. This is with Tekton Lore 98db/8ohm speakers.

My ZEN is the SE84C+ which is about a year old and has the regular (A) transformer. I have used it with only 4 ohm impedance speakers so I could not comment on what it would have been like the with B transformers. My ZEN goes up to full volume then past 3/4 volume it goes into clipping with only mild distortion that does not sound bad.

I don't know know if this will help you, but I am powering my Zu Superfly's with a Torii that I ordered with 8 and 16 ohm taps. Sounds great with both, but I like the litte extra weight the 16 ohm taps gives. I have the volume maxed and use the volume control on my Dac (2 volt) signal. I never adjust the volume more then half way, unless I am listening to high quality high rez files. Then I go a bit higher due to the transparency and smoothness of the higher rez files.

Thanks Orange! I think the 2 watt Zens are unique in that their standard transformers are set-up for lower impedance speakers and put out more power into 6, 4 and 2 ohms. I believe the other Decware amps are more traditional

SuperZen is on the way! should have it on Monday.It will be hooked up to my idecco (dac only) & Squeezebox touch to my Zu Superflys with a Rel T3 sub. What do u guys think if I used the idecco as a pre amp so I could use the remote control? Pretty sure it would degrade the sound, but was just thinking I would give it a try. Anyway I'm thrilled to finally have a Decware amp! thanks Bob

Congrats on the Super Zen being on the way! I would say try the digital volume control on the DAC. Why not? Many digital volume controls are well-implemented these days and I would suggest trying having the DAC volume about two-thirds of the way up and adjust the volume on the Super Zen until it is about your normal listening level and see what it all sounds like. . . . If you keep the DAC level in the upper range you shouldn't lose "hearable" resolution.

Wow this is great news! Thought it might suck, now i can't wait to try it. I"ll try it both ways and compare. Good to know i don't have to get another pre amp right away, not that i could right now. Thanks OC

No, i haven't pulled the trigger on those yet. Mine sound so good i don't know if i need too, but i did talk to Gerrit at zu for a minute and he said its a big improvement so im sure i'll get that bug soon. I noticed you have a squeezebox touch, nice looking system by the way,have you tried listening to MOG yet? Its very high quality! If you have a ipad you can listen to almost any artist with the touch of ur fingertips. I pay 4.99 a month and its well worth it. The app i use is squeezepad, very cool.

I have so much music, just have not got around to checking out subscription services. Usually most limit to 320 bit rate. I am very sensitive to lossy formats and even 320 I find irritating after awhile. Maybe it's all in my imagination.

I put my order in for the nanotech drivers. Zu is back ordered like Decware, so mid to end January I should receive them. I am a bit nervous as I love what I am hearing now, but then again no one I have talked to would go back. Just might mean some more tube rolling. I really can't imagine a more revealing driver, but they say it is.

I love the Anedio. I tried many other dacs but the Anedio is just so honest and revealing with sweet, smooth highs. Like a vast clear blue sunny sky. Any other Dac I tried felt like it was a bottle neck for the Torii. It's also nice having a remote control to control the volume of the Torii.

I'm getting quite a buzzing noise from the speakers now that was not there when i was using just my idecco. I've done the normal unplug this and that and its definitely coming from the idecco when i power it up. Im using it as a pre and dac. There plugged into a ps audio duet. Any suggestions?

It is, i had the volume on the Zen all the way open, so i backed it off a bit and turned the volume on the dac up a bit. Buzzing is gone. Thought i read somewhere in the post you could have it wide open but whatever. Thanks Lon

....also as Steve stated in his first post on page 1, the Essence at 12 ohm was still efficient enough that it did not matter (the 2-6 ohm he sent the Reviewer was fine). I also like being able to swap back in my current 6 to 8 ohm Speakers. No worries.... . -Stone

....what I should do is......send my SE84CS in for the Hazen Grid Mod (CCE) and the Jupiter Caps (CKC) and have option b) 6 - 16 ohm put in. I'll have my CKC to listen to while it is gone and then have both impedance Trannies when it returns.....with full upgrades on both....now I'm thinkin'.

I have a 12 year old SE84CS+ (Zen Select) and just recently received my new Super Zen with B Transformer. I have Klipsch RF-7's, 8 ohm, 101 db. I should note that my Select is bone stock so it does not have the CCE or any other mods.

Basically I unpacked the Super and swapped out the Select. First thing I noticed is that full volume (Loud for Me) the volume knob is at 12 o'clock compared to say 3 o'clock on the Select. Overall the Super will play noticeably louder with my speakers and the B output transformers.

Music detail across the full spectrum is more detailed. Instruments and vocals have much air and space between them. I have dual subs wired in stereo fashion and I had to reduce the sub volume knob setting from say 1:30 to the 11:00 o'clock position and the bass is still more audible, detailed and smoother. The top end just has a lot more sparkle.

The Super Zen has been a noticeable improvement in my system. Perhaps most surprising of all was to find out what detail my Oppo BDP-83SE, Klipsch RF-7's and HSU Subs are capable of. I was not expecting this level of improvement. The last time I made such a significant step up in my system was 12 years ago when I purchased the Select.

So is anyone hearing what im hearing from this superzen . I hope so because its a killer. I have this amp since novenber 2nd , with single drivers that are very effiecent , theres probably very few amps that are better,and I'll bet the other ones are made in Peoria . Just have to get the money to update the rest of my zens.

My office ZENSE84CKC plays louder than its predecessor, the ZENSE84C+. The difference between the behavior of these two amps has caused me to withdraw the ZSTAGE from that system. I am going bare with the ZENSE84CKC and TRAPEZIUM speakers, running CD and radio.

I am using the Valve Art 274B rectifier that DECWARE supplied with the amplifier. In addition to that I use SV83's that have about a year of play on them. The input is a 1976 black plate 6N1P-EV.

Up at DECFEST we looked at these Valve Arts labeled 274B and most believe it is electrically a 5U4G with a larger bottle. The size of the bottle alone might have some influence on the sound. However, they do a good job at this. They don't flash on startup.